Transformer.



PATENTBD MY.' 14,

L J. FRANK.

TRANSFORMER.

APPLIOATION :FILED SEH. 10.1906.

,W//n ess es JOHN rl. FRANK, Oi? SCHENCTADY,

QEW YGRK, SSIG-NGR T0 LNERAL iro. 853,778.

Specification of Letters atenc.

Pate' .ted May 14;, 190'?.

Application tiled September l0, 1906. Serial No. 333;@15,

T0 all whom 5' may cori/cern:

Be it kno wn that i, JOHN J. FRANK, e citi- Zen et the United. States, residing et Schenectady, county of Schenectady, State of Kew York, have .invented certain new und useici Improvements in Transformers, oi which the 'following is a, specification.

My invention relates lto transformers provided with regulating leads for varying` the number oi turns of one or both windings. .it has been customary heretofore to connect suoli regulating; leeds to points on winding neer its terminals. rThe introduction ot these lea-ds necessarily somewhat weakens the insulation, and it has been found in prlictice that burn-outs .here niost frequently ocs curred at the points on the windings whore the leeds are connected.

My invention. consists in connecting` the regulating; leads to points near the center of the winding, so that portions ot the winding at or neer its center are cut out in regulating the nunibcr ot turns. Since the central portion of 'the windin` ordinarily. somewhere near earth potentiel, thtl insulation ot this portion of the winding is subjected to e srnell strain, so that the weiileniiigg ot the insulzition tit this point by the introducti-on the regulating leeds becomes :i matter of srnnll importance.

My inver .ion will be best understood tir-tun. the :recoinprinting drawing: which show. i trnnsil'ornier provided with regulating leads arranged in .u: ordunce with niy inifention.

.l have illustruttwi my intention. as tpplied to the type oi liuusi'oruicr described in .Patent No. 6571245. iss-ucd to Vf. Moody, Nov. 19th, l Uhl. inwhieh the winding' is composed of independent coils mounted on opposite sides ol. n l'cctzing'uhir core und connected in series.

My intention. is particularly advantageous 'when applied to this type ot trsinstoriner, but it will he understood. thu( in. its broeder espects i t not liniitcd to this particular type.

in the drawing, represei'its s. nia etic rectangular core on. opposite sides of which ure mounted the primary und secoinlsry i, coils i3 und (l. The upper coilsr :ire eonnectl ed in the usual nnnnier to the primarir and secondary terminals l) and c, respectively.

o Zi represents regulating leeds brought out troni tlie two lower prima-ry coils. Any

two of these leads may be'connected in any suitable manner as by the connecting ineinber D, so ss to place the two sets of coils on opposite sides ot the core .in series. By connecting` diilcrent pairs of the leeds b" toget/lier, portions of the priinziry winding` lorined by the coils of B are cut out of circuit. lt will be seen tlnit the bottoni coils l'roin which the regulating leeds ere brought out, tlie coils which are subjected to the minimum potential in operation, so that the ning of the insulation ot' these coils, by y ing` out the regulating leeds, is or' small importance.

ln order to simplify the drawings I have shown the regula-ting' lends connected directly together et the bottoni of the core, but

' it will be of course, understood that this part vided with. regulatingr leeds neer its cei'itcr, iii'iiereliy si. central portion ol` the vwn'nling'v nifty be cut out oil circuit.

A. trlnistoriner winding` provided with ineens for cutting out of circuit :t portion of the turns near the center of the winding.

3. A transformer having u. winding' coniprising a. plurality of independent coils connected in series, the central coil or coils heine` provided with regulating leads whereby a.

" portion ol sind central coils nifty be cut out of i circuit.

sore, each Set comprising a plurality of coils the enfl Coll of the @they set to place the .two

Sets in series, and regula-ting leads connected.

Witnesses:

HELEN (hmmm),

to intermediate points on the end Y G. C. HOLLIS'LER.

coils which are ,connected to each other.

1u witness whereof, l have hoicunto ser. 111)' 

